From 0121805d9d2b1fff371e195c28e9b86ae38b5e47 Mon Sep 17 00:00:00 2001 From: Matthias Kaehlcke Date: Mon, 28 Jan 2019 15:46:24 -0800 Subject: kthread: Add __kthread_should_park() kthread_should_park() is used to check if the calling kthread ('current') should park, but there is no function to check whether an arbitrary kthread should be parked. The latter is required to plug a CPU hotplug race vs. a parking ksoftirqd thread. The new __kthread_should_park() receives a task_struct as parameter to check if the corresponding kernel thread should be parked. Call __kthread_should_park() from kthread_should_park() to avoid code duplication. Signed-off-by: Matthias Kaehlcke Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Steven Rostedt Cc: "Paul E . McKenney" Cc: Sebastian Andrzej Siewior Cc: Douglas Anderson Cc: Stephen Boyd Link: https://lkml.kernel.org/r/20190128234625.78241-2-mka@chromium.org --- kernel/kthread.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel/kthread.c') diff --git a/kernel/kthread.c b/kernel/kthread.c index 087d18d771b5..65234c89d85b 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -101,6 +101,12 @@ bool kthread_should_stop(void) } EXPORT_SYMBOL(kthread_should_stop); +bool __kthread_should_park(struct task_struct *k) +{ + return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(k)->flags); +} +EXPORT_SYMBOL_GPL(__kthread_should_park); + /** * kthread_should_park - should this kthread park now? * @@ -114,7 +120,7 @@ EXPORT_SYMBOL(kthread_should_stop); */ bool kthread_should_park(void) { - return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(current)->flags); + return __kthread_should_park(current); } EXPORT_SYMBOL_GPL(kthread_should_park); -- cgit v1.2.3 From fe99a4f4d6022ec92f9b52a5528cb9b77513e7d1 Mon Sep 17 00:00:00 2001 From: Julia Cartwright Date: Tue, 12 Feb 2019 17:25:53 +0100 Subject: kthread: Convert worker lock to raw spinlock In order to enable the queuing of kthread work items from hardirq context even when PREEMPT_RT_FULL is enabled, convert the worker spin_lock to a raw_spin_lock. This is only acceptable to do because the work performed under the lock is well-bounded and minimal. Reported-by: Steffen Trumtrar Reported-by: Tim Sander Signed-off-by: Julia Cartwright Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Tested-by: Steffen Trumtrar Reviewed-by: Petr Mladek Cc: Guenter Roeck Link: https://lkml.kernel.org/r/20190212162554.19779-1-bigeasy@linutronix.de --- kernel/kthread.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) (limited to 'kernel/kthread.c') diff --git a/kernel/kthread.c b/kernel/kthread.c index 087d18d771b5..5641b55783a6 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -599,7 +599,7 @@ void __kthread_init_worker(struct kthread_worker *worker, struct lock_class_key *key) { memset(worker, 0, sizeof(struct kthread_worker)); - spin_lock_init(&worker->lock); + raw_spin_lock_init(&worker->lock); lockdep_set_class_and_name(&worker->lock, key, name); INIT_LIST_HEAD(&worker->work_list); INIT_LIST_HEAD(&worker->delayed_work_list); @@ -641,21 +641,21 @@ repeat: if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); worker->task = NULL; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); return 0; } work = NULL; - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); if (!list_empty(&worker->work_list)) { work = list_first_entry(&worker->work_list, struct kthread_work, node); list_del_init(&work->node); } worker->current_work = work; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); if (work) { __set_current_state(TASK_RUNNING); @@ -812,12 +812,12 @@ bool kthread_queue_work(struct kthread_worker *worker, bool ret = false; unsigned long flags; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); if (!queuing_blocked(worker, work)) { kthread_insert_work(worker, work, &worker->work_list); ret = true; } - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_queue_work); @@ -843,7 +843,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) if (WARN_ON_ONCE(!worker)) return; - spin_lock(&worker->lock); + raw_spin_lock(&worker->lock); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @@ -852,7 +852,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) list_del_init(&work->node); kthread_insert_work(worker, work, &worker->work_list); - spin_unlock(&worker->lock); + raw_spin_unlock(&worker->lock); } EXPORT_SYMBOL(kthread_delayed_work_timer_fn); @@ -908,14 +908,14 @@ bool kthread_queue_delayed_work(struct kthread_worker *worker, unsigned long flags; bool ret = false; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); if (!queuing_blocked(worker, work)) { __kthread_queue_delayed_work(worker, dwork, delay); ret = true; } - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_queue_delayed_work); @@ -951,7 +951,7 @@ void kthread_flush_work(struct kthread_work *work) if (!worker) return; - spin_lock_irq(&worker->lock); + raw_spin_lock_irq(&worker->lock); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @@ -963,7 +963,7 @@ void kthread_flush_work(struct kthread_work *work) else noop = true; - spin_unlock_irq(&worker->lock); + raw_spin_unlock_irq(&worker->lock); if (!noop) wait_for_completion(&fwork.done); @@ -996,9 +996,9 @@ static bool __kthread_cancel_work(struct kthread_work *work, bool is_dwork, * any queuing is blocked by setting the canceling counter. */ work->canceling++; - spin_unlock_irqrestore(&worker->lock, *flags); + raw_spin_unlock_irqrestore(&worker->lock, *flags); del_timer_sync(&dwork->timer); - spin_lock_irqsave(&worker->lock, *flags); + raw_spin_lock_irqsave(&worker->lock, *flags); work->canceling--; } @@ -1045,7 +1045,7 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker, unsigned long flags; int ret = false; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); /* Do not bother with canceling when never queued. */ if (!work->worker) @@ -1062,7 +1062,7 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker, fast_queue: __kthread_queue_delayed_work(worker, dwork, delay); out: - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); return ret; } EXPORT_SYMBOL_GPL(kthread_mod_delayed_work); @@ -1076,7 +1076,7 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork) if (!worker) goto out; - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @@ -1090,13 +1090,13 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork) * In the meantime, block any queuing by setting the canceling counter. */ work->canceling++; - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); kthread_flush_work(work); - spin_lock_irqsave(&worker->lock, flags); + raw_spin_lock_irqsave(&worker->lock, flags); work->canceling--; out_fast: - spin_unlock_irqrestore(&worker->lock, flags); + raw_spin_unlock_irqrestore(&worker->lock, flags); out: return ret; } -- cgit v1.2.3 From ad01423aedaa7c6dd62d560b73a3cb39e6da3901 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 12 Feb 2019 17:25:54 +0100 Subject: kthread: Do not use TIMER_IRQSAFE The TIMER_IRQSAFE usage was introduced in commit 22597dc3d97b1 ("kthread: initial support for delayed kthread work") which modelled the delayed kthread code after workqueue's code. The workqueue code requires the flag TIMER_IRQSAFE for synchronisation purpose. This is not true for kthread's delay timer since all operations occur under a lock. Remove TIMER_IRQSAFE from the timer initialisation and use timer_setup() for initialisation purpose which is the official function. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Reviewed-by: Petr Mladek Link: https://lkml.kernel.org/r/20190212162554.19779-2-bigeasy@linutronix.de --- kernel/kthread.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/kthread.c') diff --git a/kernel/kthread.c b/kernel/kthread.c index 5641b55783a6..537335541267 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -835,6 +835,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) struct kthread_delayed_work *dwork = from_timer(dwork, t, timer); struct kthread_work *work = &dwork->work; struct kthread_worker *worker = work->worker; + unsigned long flags; /* * This might happen when a pending work is reinitialized. @@ -843,7 +844,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) if (WARN_ON_ONCE(!worker)) return; - raw_spin_lock(&worker->lock); + raw_spin_lock_irqsave(&worker->lock, flags); /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); @@ -852,7 +853,7 @@ void kthread_delayed_work_timer_fn(struct timer_list *t) list_del_init(&work->node); kthread_insert_work(worker, work, &worker->work_list); - raw_spin_unlock(&worker->lock); + raw_spin_unlock_irqrestore(&worker->lock, flags); } EXPORT_SYMBOL(kthread_delayed_work_timer_fn); -- cgit v1.2.3 From 98fa15f34cb379864757670b8e8743b21456a20e Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Tue, 5 Mar 2019 15:42:58 -0800 Subject: mm: replace all open encodings for NUMA_NO_NODE Patch series "Replace all open encodings for NUMA_NO_NODE", v3. All these places for replacement were found by running the following grep patterns on the entire kernel code. Please let me know if this might have missed some instances. This might also have replaced some false positives. I will appreciate suggestions, inputs and review. 1. git grep "nid == -1" 2. git grep "node == -1" 3. git grep "nid = -1" 4. git grep "node = -1" This patch (of 2): At present there are multiple places where invalid node number is encoded as -1. Even though implicitly understood it is always better to have macros in there. Replace these open encodings for an invalid node number with the global macro NUMA_NO_NODE. This helps remove NUMA related assumptions like 'invalid node' from various places redirecting them to a common definition. Link: http://lkml.kernel.org/r/1545127933-10711-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: David Hildenbrand Acked-by: Jeff Kirsher [ixgbe] Acked-by: Jens Axboe [mtip32xx] Acked-by: Vinod Koul [dmaengine.c] Acked-by: Michael Ellerman [powerpc] Acked-by: Doug Ledford [drivers/infiniband] Cc: Joseph Qi Cc: Hans Verkuil Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kthread.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/kthread.c') diff --git a/kernel/kthread.c b/kernel/kthread.c index 087d18d771b5..ebebbcf3c5de 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -20,6 +20,7 @@ #include #include #include +#include #include static DEFINE_SPINLOCK(kthread_create_lock); @@ -675,7 +676,7 @@ __kthread_create_worker(int cpu, unsigned int flags, { struct kthread_worker *worker; struct task_struct *task; - int node = -1; + int node = NUMA_NO_NODE; worker = kzalloc(sizeof(*worker), GFP_KERNEL); if (!worker) -- cgit v1.2.3